Various techniques have been proposed for dispersing a relatively viscous material in a relatively less viscous material. U.S. Pat. No. 2,598,500 to Burke describes agitating apparatus including a matrix of closely spaced vibratable wires and contains a statement to the effect that the device can be used as a mixer wherein one or more fluids may be introduced to the wires through a common inlet.
U.S. Pat. No. 3,132,845 to Norty describes a vibratory mixer having particular utility in mixing materials of high viscosity wherein such materials may be supplied via two inlets to a rotating blade which provides preliminary mixing and thence to a vibratory actuator wherein they are forced through perforations therein.
U.S. Pat. No. 557,892 to Root describes a machine for mixing or blending flours including a premixing stage followed by an agitating stage.
U.S. Pat. No. 3,925,243 to Brogli et al describes apparatus for manufacturing emulsions wherein a liquid to be emulsified is injected directly into the periphery of a stirrer that is rotated in a liquid in which the emulsion is to be made.
U.S. Pat. No. 4,347,002 to Born describes a method and apparatus for the preparation of drilling mud employing reciprocating perforated plates which move back and forth, towards and away from each other, thus forcing the constituents of the drilling mud through the perforations and producing mixing thereof.
German Laid Open Patent Application 3725002 A1, published on Feb. 4, 1988, less than one year prior to the filing of this application, describes inter alia and illustrates in FIG. 16 a toner disperser including an apertured drum in which is disposed a driven spiral disperser. A concentrated toner is supplied to the interior of the apertured drum and passes out through the apertures therein to a dispersing liquid.